Numerous types of window coverings are now being sold at a variety of outlets. Window coverings of the type with which the present invention is concerned include mini blinds as opposed to draperies and curtains which may be sold in the same outlets but which involve different sizing requirements.
The types of outlets that sell mini blinds include custom specialty shops and department stores which usually ask the customer for window dimensions and then submit orders to factories or distribution centers where the products are cut to a specific size. Not only must the customer make two visits to these outlets to obtain the product, but the custom mini blinds are relatively expensive.
Mass merchandisers also distribute mini blinds. In many such outlets, only stocked sizes are carried, because some windows, especially in newer homes and offices, are of standard dimensions. These mini blinds are usually much less expensive than those obtained from custom outlets because of the economies realized from carrying a limited stock of sizes, and because there are no sizing operations which must be performed on the products.
In recent years, a third option has been made available to the customer. This option involves the in-store sizing of mini blinds and various other window coverings to customer specifications. An example of how in-store sizing can be accomplished is disclosed in commonly owned U.S. Pat. No. 5,072,494, issued Dec. 17, 1991 to Graves et al. for "Method and Apparatus for Infinitely Sizing a Mini Blind" and its parent, U.S. Pat. No. 4,993,131, issued Feb. 19, 1991 to the same inventors and with the same title. In the device shown in these patents, mini blinds of a specific design are sized to customer specifications on a machine. The mini blind itself includes a head rail, a bottom rail, a plurality of slats, a tilter bar, and a rope system having ladders for raising and lowering the slats and for locking the blind in a desired open or closed position. The mini blind product used with the system illustrated in these two patents includes one ladder fixed in place. The other ladder is not installed at the factory, but is placed over the slats near the installed ladder. To custom size the mini blind in the store, the blind is cut on one side, with the cutting apparatus cutting through the head rail, bottom rail, and each of the individual slats. A drill is then used to provide holes in each of the blind slats at a location picked by the operator to match the spacing of the installed ladder. The two ladders are thus spaced to the same distance from the ends of the blind. The unsecured ladder is then moved into alignment with the holes and a cord is passed through the slats and secured at the bottom rail.
The cutter used to cut the mini blinds is constructed of structurally strong materials to allow the plurality of slats and the bottom rail to be cut in a single cutting operation in most circumstances. The slats are disposed adjacent one another as the adjacent ends along one side are slid into the cutter. A cutter blade mounted on a cutting bar and appropriately configured to provide the ends of the slats with the desired shape, is then moved tightly against the stack of adjacent slats. A cutting mechanism, typically using either a pump or a cutting bar rack driven by a pawl attached to a lever, moves the cutting bar and attached knife into and through the bottom rail and slat material. One problem with some of these cutters is that insufficient leverage makes it difficult to cut mini blinds unless the cutting machine and lever are quite large. Another problem is rapid wear on the cutter blade particularly when cutting aluminum.
Due to the difficulty encountered in cutting all of the components of a blind in one operation, it is also often desirable to cut the head rail of the mini blind either alone or consecutively with the cutting of the slats. A space is provided in the cutter for receiving an end of the head rail and sometimes the cutter also includes a center portion disposed for insertion into the head rail to help hold it in place. One problem with this arrangement is that the head rail is not held securely enough to provide a high quality cut. This is particularly a problem, when the head rail has various grooves, slots, or other complex shapes which sometimes tend to cause a greater twisting action when being cut by the knife.